This week we are going to step into the world of acoustics. It’s a topic that often confuses many and with so many details involved, it’s important to have a good understanding of how your decisions (STC rating, fire-rating, lites, gaskets, frames) will affect the acoustic performance of the opening. First, let’s discuss the frames.
Q: What are the frame requirements of your acoustic doors?
A: We recommend that you install our acoustic doors in steel frames fully grouted with cement. This is how we conduct our tests. It allows us to ensure that the resulting STC rating represents only the door and gasketing system. Our goal is to avoid dealing with any deficiencies due to the frame.
This is not, however, meant to restrict the openings in which our acoustic doors are used. In many circumstances, existing frames or installation conditions may prevent the use of a solid filled frame. Where other types of fill are used, an acoustic consultant should be employed to determine if the alternate fill will maintain the desired acoustic performance for the opening.
As long as the framing provides an acoustic performance equal or greater than the door rating, the advertised STC will be maintained.
Another question that is often raised in regards to acoustical doors is:
Q: What happens to acoustical ratings when substitutions are made to lite sizes or glazing systems?
A: In our Product Offering Chart, you’ll notice that some lite sizes are listed as “Min.” and some are listed as “Max.” beneath the Glazing Area (sq. in.) column. We note this to help explain how the glass is performing in that particular door. If the lite size is listed as “min.” – the glass is performing better than the core, therefore, reducing the size of the lite opening will drop the STC rating. Just the opposite is true for lites with “Max.” As STC ratings climb, adding lites drops the STC rating by an average of 2 points, depending upon the opening size and the type of glazing used.
We do not, however, know what will happen in every situation and an acoustic consultant should be consulted whenever significant changes are made to how our doors were originally tested.
For ratings up to the low 40’s, there are laminated glass and IGU glazing options that provide similar STC ratings. Laminated insulating units are typically required for higher STC ratings.
Here are some useful resources to help you select the best acoustical product to meet the needs of your next project.